The hashcash-x.xx-exe.zip files contain HASHCASH.EXE, SHA1.EXE win32 console applications plus documentation. The HASHCASH.EXE, SHA1.EXE and HASHCASH.DLL are always from the latest 1.x version. People using 3rd party apps that use the HASHCASH.DLL can just copy the latest and replace it. The hashcash-x.xx-dll.zip files contain HASHCASH.DLL, HASHCASH.LIB plus a HASHCASH.EXE built to require the HASHCASH.DLL. These are for people who want to link software using the HASHCASH.DLL. The .asc files are signatures of the .zip file and .exe files. The old 0.3x exes are in the associated 0.3x .zip. In general version 0 stamps are deprecated and should be phased out. But the 0.3x exes are retained as a way to generate version 0 stamps for people who need a way to do that for legacy apps. The 1.x exes can produce version 1 stamps only, but can verify both version 0 and version 1 stamps.